Transaction Resource Managers

There are three types of transaction resource managers:

Databases - Use
of transactions prevents databases from being left in inconsistent
states due to incomplete updates. For information about JDBC transaction
isolation levels, see Using JDBC Transaction Isolation Levels.

Java Message Service (JMS) Providers - Use
of transactions ensures that messages are reliably delivered. The GlassFish Server is
integrated with GlassFish Message Queue, a fully capable JMS provider.
For more information about transactions and the JMS API, see Chapter 17, Using the Java Message Service.

J2EE Connector Architecture (CA)
components - Use of transactions prevents legacy EIS systems from
being left in inconsistent states due to incomplete updates. For more
information about connectors, see Chapter 12, Developing Connectors.